English verb conjugation
COULD PEN

Regular verb: pen - penned - penned

Affirmation

Simple form	V-ing form
I could pen you could pen he could pen we could pen you could pen they could pen	I could be penning you could be penning he could be penning we could be penning you could be penning they could be penning
Perfect	V-ing perfect
I could have penned you could have penned he could have penned we could have penned you could have penned they could have penned	I could have been penning you could have been penning he could have been penning we could have been penning you could have been penning they could have been penning

Negation

Simple form	V-ing form
I couldn't pen you couldn't pen he couldn't pen we couldn't pen you couldn't pen they couldn't pen	I couldn't be penning you couldn't be penning he couldn't be penning we couldn't be penning you couldn't be penning they couldn't be penning
Perfect	V-ing perfect
I couldn't have penned you couldn't have penned he couldn't have penned we couldn't have penned you couldn't have penned they couldn't have penned	I couldn't have been penning you couldn't have been penning he couldn't have been penning we couldn't have been penning you couldn't have been penning they couldn't have been penning

Interrogative form

Simple form	V-ing form
could I pen? could you pen? could he pen? could we pen? could you pen? could they pen?	could I be penning? could you be penning? could he be penning? could we be penning? could you be penning? could they be penning?
Perfect	V-ing perfect
could I have penned? could you have penned? could he have penned? could we have penned? could you have penned? could they have penned?	could I have been penning? could you have been penning? could he have been penning? could we have been penning? could you have been penning? could they have been penning?

Interro-negative form

Simple form	V-ing form
couldn't I pen? couldn't you pen? couldn't he pen? couldn't we pen? couldn't you pen? couldn't they pen?	couldn't I be penning? couldn't you be penning? couldn't he be penning? couldn't we be penning? couldn't you be penning? couldn't they be penning?
Perfect	V-ing perfect
couldn't I have penned? couldn't you have penned? couldn't he have penned? couldn't we have penned? couldn't you have penned? couldn't they have penned?	couldn't I have been penning? couldn't you have been penning? couldn't he have been penning? couldn't we have been penning? couldn't you have been penning? couldn't they have been penning?